In recent years, methods of testing a target gene of an analyte which have been widely performed for molecular diagnosis mainly include quantitative methods and qualitative methods.
A quantitative method is a method of relatively or absolutely measuring an expression level and a copy number of a target gene. On the other hand, a qualitative method is a method of determining the presence and genotype of a target gene.
A representative method for quantitative analysis is a method using a real-time polymerase chain reaction (PCR). The analytic methods using real-time PCR have been widely used since they have advantages in that quantitative analysis is possible, and that it is possible to reduce the risk of contamination by the air since genetically amplified signals are obtained without opening a tube after an analyte is mixed with a reagent. However, such methods have problems in that it is difficult to analyze six or more different types of analytes since a maximum of six fluorescent materials may be analyzed in one tube at the same time, and thus the analytes should be assigned to and tested in several tubes when there are several tens of genetic mutations and genotypes of the analytes to be tested.
A representative method for qualitative analysis is a method using a DNA microarray. The analytic method using a DNA microarray has an advantage in that one kind of fluorescence may be used to test various genotypes at a time since a number of target probes are fixed on a surface of one support, but has a limitation in that it is impossible to quantitatively analyze the genotypes.